1. Field of the Invention
The present invention generally relates to a system and method for recovering resolution in an x-ray computed tomography system.
2. Description of Related Art
In a typical x-ray computed tomography system, an x-ray source projects an x-ray beam through an object and onto a detector. The x-ray source is generally thought of as a point source. However, the focal spot of the x-ray source is actually projected onto a surface and, therefore, has a different apparent size and shape depending on the perspective angle relative to the surface. The projection of an extended focal spot onto the detector may result in significant blur. This system blur is shift variant and depends on the exact geometry of the computed tomography system and the shape of the focal spot. Typically this form of system blur is ignored and mitigated by construction of an x-ray source with a smaller focal spot. This places extraordinary demands on x-ray source design since energy is concentrated on smaller areas of the x-ray target. Such requirements have led to large rotating anode sources with sophisticated mechanisms for removing excess heat. With the simultaneous drive for ever smaller reconstructed voxel sizes and physically smaller computed tomography systems, it may be helpful to approach this problem from both the source design and the data processing sides.
In view of the above, it is apparent that there exists a need for a system and method for recovering resolution in an x-ray computed tomography system.